Are you in the Company of Champions Covenant?

or it might be just because you're not human

If you're referring to the Black Gulch, you have to find and talk to her first. Then her summon symbol will appear next to the hidden bonfire.

This wiki is complete garbage, I'd recommend reading it thoroughly before doing anything if you're achievement hunting.

This is why you need to make constant and multiple backups of your save file. Lesson learned the hard way.

This is why you need to make constant and multiple backups of your save file throughout your progression through the game. Lesson learned the hard way

What part of the Solaire / Siegward questlines lets you combine them both into one jolly cooperator

The sole fact that you put solaire in 4th place offends me.

Solaire switched with hanbei and the numbers flipped and then youve got it right

I don’t see Galvan on this list

1. Isn't hanbei from sekiro?
2. How hanbei is better than isshin?
3. My tier list:
5) Patches the Hyena
4) Trusty Patches
3) Unbreakable Patches
2) Patches the Spider
1) Patches the Untethered

Honorable Mention
Amnesiac Lapp

Solaire should be at #1

I fought the rotten 3 times on NG+ to get this done, so NG+4. Just clear out all the poison statues, hand monsters, and centipedes before the fog gate, summon the 2 extra summons in Black Gulch, and equip the Redeye Ring and try your best to bait the attacks. Easiest boss fight in the game.

You need to really DPS race I. The rotten on higher difficulties if lucatiel has aggro.
While an easy boss the rotten does has impressive damage, he can usually two shot you.

The red eye ring won't make you a target 100% of the time. Enemies will still switch targets randomly, but the ring does help, they're more likely to stick to you.

Try to manipulate the agro with a weapon that hits hard. Grab agro, run to the Rotten's far side and bait his reach attack. Keep mid distance without attacking until he switches agro to her. Then go wail on his back until he turns around. Rinse and repeat. If you attack the whole time, she ends up on the same side as you. Thus, all the attacks aimed at you hit her. I use a Black Knight Sword at around +3. Anything that deals damage hard and fast works. Do it right and she survives even on higher ng+ cycles.

I think you can use bonefire assetics to get a +1 to the number of times she helped you. This is unconfirmed, but id try that

Like the guy above said,
bonefire assetics work. I use it to summon her for flexile sentery since I miss the summon in my first fight. I found her in aldia's keep

Nvm I was using the pre-SoTFS location